Re: [PATCH] python: Replace asyncio.get_event_loop for Python 3.14

["Richard W.M. Jones" <rjones@redhat.com>]

On Tue, Jul 15, 2025 at 12:54:26PM +0200, Miro Hrončok wrote:
> On 15. 07. 25 12:51, Richard W.M. Jones wrote:
> >In Python 3.14, no asyncio event loop gets generated automatically.
> >Instead create one when we need it.  This should work with Python 3.13
> >as well.  This is a mechanical change as suggested here:
> >
> >https://bugzilla.redhat.com/show_bug.cgi?id=2375004#c4
> >
> >See-also: https://docs.python.org/3.14/whatsnew/3.14.html#id7
> >Thanks: Miro Hrončok
> >Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
> >---
> >  python/qemu/qmp/legacy.py  | 5 ++++-
> >  python/qemu/qmp/qmp_tui.py | 5 ++++-
> >  python/qemu/qmp/util.py    | 5 ++++-
> >  python/tests/protocol.py   | 5 ++++-
> >  4 files changed, 16 insertions(+), 4 deletions(-)
> >
> >diff --git a/python/qemu/qmp/legacy.py b/python/qemu/qmp/legacy.py
> >index 22a2b5616e..e11d05afbd 100644
> >--- a/python/qemu/qmp/legacy.py
> >+++ b/python/qemu/qmp/legacy.py
> >@@ -86,7 +86,10 @@ def __init__(self,
> >                  "server argument should be False when passing a socket")
> >          self._qmp = QMPClient(nickname)
> >-        self._aloop = asyncio.get_event_loop()
> >+        try:
> >+            self._aloop = asyncio.get_event_loop()
> >+        except RuntimeError:
> >+            self._aloop = asyncio.new_event_loop()
> >          self._address = address
> >          self._timeout: Optional[float] = None
> >diff --git a/python/qemu/qmp/qmp_tui.py b/python/qemu/qmp/qmp_tui.py
> >index 2d9ebbd20b..84c5da4e66 100644
> >--- a/python/qemu/qmp/qmp_tui.py
> >+++ b/python/qemu/qmp/qmp_tui.py
> >@@ -377,7 +377,10 @@ def run(self, debug: bool = False) -> None:
> >          screen = urwid.raw_display.Screen()
> >          screen.set_terminal_properties(256)
> >-        self.aloop = asyncio.get_event_loop()
> >+        try:
> >+            self.aloop = asyncio.get_event_loop()
> >+        except RuntimeError:
> >+            self.aloop = asyncio.new_event_loop()
> >          self.aloop.set_debug(debug)
> >          # Gracefully handle SIGTERM and SIGINT signals
> >diff --git a/python/qemu/qmp/util.py b/python/qemu/qmp/util.py
> >index ca6225e9cd..8f9f849a5f 100644
> >--- a/python/qemu/qmp/util.py
> >+++ b/python/qemu/qmp/util.py
> >@@ -160,7 +160,10 @@ def asyncio_run(coro: Coroutine[Any, Any, T], *, debug: bool = False) -> T:
> >          return asyncio.run(coro, debug=debug)
> >      # Python 3.6
> >-    loop = asyncio.get_event_loop()
> >+    try:
> >+        loop = asyncio.get_event_loop()
> >+    except RuntimeError:
> >+        loop = asyncio.new_event_loop()
> >      loop.set_debug(debug)
> >      ret = loop.run_until_complete(coro)
> >      loop.close()
> 
> This one particular addition should not be necessary as it only runs
> on Python 3.6. This code is not reached on Python 3.7+ and hence it
> is not reached on Python 3.14.

Yup, even says it in the comment :-)

I'll submit a v2 in a little while, in case there is any other feedback.

Rich.

> >diff --git a/python/tests/protocol.py b/python/tests/protocol.py
> >index 56c4d441f9..aa7c0e4397 100644
> >--- a/python/tests/protocol.py
> >+++ b/python/tests/protocol.py
> >@@ -228,7 +228,10 @@ def async_test(async_test_method):
> >          Decorator; adds SetUp and TearDown to async tests.
> >          """
> >          async def _wrapper(self, *args, **kwargs):
> >-            loop = asyncio.get_event_loop()
> >+            try:
> >+                loop = asyncio.get_event_loop()
> >+            except RuntimeError:
> >+                loop = asyncio.new_event_loop()
> >              loop.set_debug(True)
> >              await self._asyncSetUp()
> 
> -- 
> Miro Hrončok
> -- 
> Phone: +420777974800
> Fedora Matrix: mhroncok

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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